Artificial dielectric device for heating gases with electromagnetic energy

ABSTRACT

A device for thermal treatment of gases and pollutants employs alternate cavity ( 1 ) and susceptor ( 9 ) geometries for providing more homogeneous interactions of applied electromagnetic energy ( 6 ) in the volume of the susceptor ( 9 ) regardless of the flow rate and diameter of the exhaust duct ( 3 ) width. The heat transfer methods improve the overall heat efficiency of the device. The susceptor ( 9 ) structure has reflectivity as principle mode of interaction with applied electromagnetic energy ( 6 ) which allows for energy to penetrate the susceptor ( 9 ) which is formed of composite susceptive materials. The use of field concentrators ( 5 ) to concentrate the energy density of the applied electromagnetic energy ( 6 ) provides a simple method of controlling the temperature versus energy in the susceptor ( 9 ).

This application is a 371 of PCT/US98/06647 filed Apr. 3, 1998 and alsoclaims the benefit of Provisional No. 60/041,942 filed Apr. 4, 1997.

BACKGROUND OF THE INVENTION

Field of Invention

This invention relates to a device and process for thermal treatment ofwaste gases and reactive gases. The invention is used for thedestruction and reduction of pollutants from effluent waste streams, andto produce gaseous products from reactant gases.

BACKGROUND

Devices which operate on electricity to thermally treat gases fromwastestreams to reduce pollution and thermally react gases for synthesisof products do not rely on natural gas for supplying energy. Devicesthat use natural gas to produce energy for such applications createcarbon dioxide, carbon monoxide and nitrogen oxides from the energysource. Electricity is consider to have cleaner operation when used insuch devices since the above chemical species are not produced duringoperation from the heat source. Electric devices for pollution controlapplications produce less pollution at the point source when compared tothe counter technologies operating on natural gas. The reduced pollutionis favorable to reduce greenhouse gases and to the meet the requirementsof the Clean Air Act of 1990. There are many types of electric heatingmethods, this discussion will focus on designs used to produce heat andreaction with applied electromagnetic energy.

The scope of this current invention is a device for thermal treatment ofgases and pollutants 1) that employs alternate cavity and susceptorgeometries for providing more homogeneous interactions of appliedelectromagnetic energy in the volume of the susceptor regardless of theflow rate and diameter of the exhaust duct width, 2) heat transfermethods to improve the overall heat efficiency of the device, 3) asusceptor structure which has reflectivity as principle mode ofinteraction with applied electromagnetic energy which allows for energyto penetrate a susceptor, 4) composite susceptor materials, 5) a simplemethod of controlling the temperature versus energy concentration in thesusceptor and 6) field concentrators to concentrate the energy densityof the applied electromagnetic energy.

BACKGROUND

Cavity geometries in these devices effect the optical properties of theelectromagnetic energy within the susceptor. Electromagnetic energy,whether the frequency is either ultraviolet, infra red, microwave orradio frequencies, exhibit the same optical properties as the visiblespectrum when interacting with geometric shapes and surfaces which aresimilar to a lens. The electromagnetic energy in a susceptor can eitherconverge or diverge due to the geometric shape of the susceptorfollowing the same principles as optical lenses. Additionally the modesof propagation of the electromagnetic energy is dependent upon thecavities geometry. These modes effect the distribution ofelectromagnetic energy in the cavity. These modes are different forcylindrical and rectangular cavities (Handbook of MicrowaveEngineering).

Electromagnetic energy, which is incident perpendicular to the perimeterof circular cross-section of a cylindrical susceptor, will cause theenergy to converge initially, concentrating the energy within thecross-section. This concentration will cause the material inside thesusceptor to absorb more energy than the material near the surface,changing the dielectric properties of the material inside thecross-section. This concentration of energy can make the material whichis located in the susceptor's interior, between the center and theperimeter, to absorb more energy, thereby reducing the depth ofpenetration of the material due to the susceptor's geometry. The opticalproperties of rectangular cavities and planar surfaces are different.Rectangular cavities with a susceptor having a rectangular geometry andplanar surfaces will follow the optical properties of a flat surface. Aflat surface does concentrate or disperse energy as curved surfaces,convex and concave. With a flat surface of incidence for appliedelectromagnetic energy, the absorption of electromagnetic energy in asusceptor is due only to the materials properties and is not influencedby energy which is concentrated by curved geometries. Incident energy onsusceptors with flat surfaces will not concentrate energy within astructure with homogeneous material, and the depth of penetration willbe influenced by the incident energy's power, the electric fields andmagnetic fields inside the susceptor. Conversely, incident energy onsusceptors with curved geometry can concentrate energy within asusceptor with homogeneous materials, and the depth of penetration ofthe energy will be influenced by the ability of the curved surface toconcentrate energy inside the susceptor.

The overall energy efficiency of such devices for thermal treatment ofgases can be improve with a better heat transfer process to capture thatenergy that is lost from cooling the tube which is the source for theapplied electromagnetic energy. In industrial microwave dryingoperations, the heat produced from cooling the magnetrons with air isapplied to the articles which are being dried with the microwaves. Thissynergistic drying which uses hot air and microwaves, increases theenergy efficiency of the drying process.

Alternative composite materials and susceptor structures can be use tofacilitate the thermal treatment of gases. These composite materials andsusceptor structures are known as artificial dielectrics.

Artificial dielectric structures date back to the 1940's. Artificialdielectric were used as lenses to focus radio waves for communication(Koch). Artificial dielectric use conductive metal plates, rods, spheresand discs (second phase material) which are embedded in matrices of lowdielectric constants and low dielectric losses to increase the index ofrefraction, thus reducing size of a lens to achieve the desired opticalproperties. The second phase material reflects the energy and usesdiffusse reflection to transmit electromagnetic energy. These plates,rods, spheres and discs can be arranged in a lattice structure toproduce an isotropic or anisotropic structure. When conductive elementsare embedded in a low dielectric constant and low dielectric lossmatrix, the effect of these on the matrix material's dielectric lossfactor is negligible and the dielectric constant of the composite lensis increased. However, these above effects are limited and influenced bythe size, shape, conductivity and volume fraction of the materialembedded in a materials of low dielectric loss, low dielectric constantof the material as well as the wavelength of the incident radiation. Thedielectric strength and complex dielectric constant of the matrixmaterial plays important additional roles in the design of artificialdielectric lenses. On the other hand, selection of matrix materials withdifferent dielectric properties and incorporation second phase materialssuch as semiconductors, ferroelectrics, ferromagnetics,antiferroelectrics, antifermagnetics, dielectrics with higher dielectriclosses, dielectrics with conductive losses produce absorption ofmicrowave energy, producing heat in an artificial dielectric.

Lossy artificial dielectrics have been demonstrated by the 1950's, andsubsequently used at the microwave frequencies to sinter ceramicarticles, in food packaging for heating food stuffs, browningapparatuses for foodstuffs, consumer products, and to render adhesivesflowable for bonding applications.

The structure of the artificial dielectric determines theelectromagnetic properties. When the volume fraction of the 2nd phasematerials inside the artificial dielectric reaches a certain level, theartificial dielectric will reflect incident electromagnetic energy,shielding the artificial dielectric from absorbing electromagneticenergy. The volume fraction of the 2nd phase material at which theartificial dielectric shields electromagnetic energy is dependent on the2nd phase material's reflectivity, the shape of the 2nd phase materialand temperature. By controlling the amount of reflection, thesusceptor's reflectivity can be used to control the susceptor'stemperature.

Reflectivity has been used to produce sutures which have a self-limitingtemperature. Producing reflectivity in dielectrics is explain in VonHipple's Dielectrics and Waves. Using such principles, devices have beendesign to be self-limiting temperatures Self-limiting temperatures havealso been theorized for materials with Curie Temperatures Thereflectivity of electromagnetic energy is related to a material'conductivity. Metals are electrically conductive at room temperaturesand reflect electromagnetic energy. Semiconductors and ionic conductorshave low moderate conductivity at room temperature. At elevatedtemperatures semiconductors and ionic conductors have increasedconductivity, and these materials will become reflective toelectromagnetic energy at elevated temperatures. The amount ofreflectivity of a material at elevated temperature will also bedependent upon the wavelength of incident electromagnetic energy.

The artificial dielectrics structure can be used to produce diffusereflection, scattering, inside a susceptor. The 2nd phase materials caneither be reflective materials at room temperature, such as a metal, orbecome reflective at elevated temperatures due to 1) increasedconductivity, such as semiconductors and ionic conductors and/or 2)exceeding the Curie temperature, such as ferroelectrics andferromagnetics. This diffuse reflection may also be used to control thetemperature of a given susceptor that uses the artificial dielectricstructure.

Regardless of the structure of a susceptor and materials ofconstruction, applied energy must be a applied to penetrate thestructure and material or materials of construction for volumetricinteraction between the susceptor and the applied energy.

Other considerations must be given to the structure of a susceptor in adevice for thermal treatment of gases. Honeycombs, foams, packedmaterial and woven structures which are constructed of a material thateither have an increased dielectric conductivity at elevatedtemperatures or have a Curie Temperature below the operating temperaturecould become reflective. If the material becomes reflective, then thesusceptors structure could either a) act as waveguides with dimensionsthat would not allow the applied energy to penetrate because the appliedenergy would be below the cut-off frequency for the susceptor'sstructure or b) shield the electromagnetic energy from penetrating intothe susceptor. The Handbook of Microwave Engineering Handbook explainswaveguide theory in more detail. When Granular suscepting structuresemployed in U.S. Pat. No. 4,718,358 for treatment of gases exemplifyconditions where the susceptor's structure may not allow for incidentelectromagnetic energy penetrate the volume of the susceptor.

It seems to appear that the authors of U.S. Pat. No. 4,718,358preferably embody granular absorbing material in the range of about 5 mmto 10 mm with a layer thickness which is preferably 100 mm to 300 mm.One of the preferred absorbing materials is SiC in granular form.Silicon Carbide, a semi-conducting ceramic, has a moderate penetrationdepth of approximately 10 cm at room temperature. And, depending uponthe purity of the SiC, the depth of penetration can be less then 2 cm atroom temperature. At elevated temperatures, silicon carbide becomes moreconductive, thus having an even lower penetration depth. If one assumesthat the granules in U.S. Pat. No. 4,718,358 are spherical, then the 10mm spheres of the SiC would most likely pack inside the cylindricalcavity as what is known as the close-packed cubic structure. Theclose-pack cubic SiC structure would have a void volume of only 26%. Thelargest void space in this granular pack of 10 mm SiC spheres in theclose-pack cubic structure would be occupied what is known as anoctahedral site. The octahedral site is the void space between sixspheres—four spheres touching in one plane, one on the top of and one onthe bottom of the void space formed between the four-spheres-touching inone plane. The void diameter of the octahedral site at the largestdiameter would be about 6 mm. With an open space of the 6 mm in widthand the device in U.S. Pat. No. 4,718,358 operating at approximately900° C., where the dielectric conductivity of SiC is greatly increasedin comparison to the dielectric conductivity at room temperature, onecan question the ability of the microwave energy at 2.45 GHz andwavelength of approximately 13 cm to propagate through the close-packcubic structure of the SiC granules and heat a volume of SiC with adepth of the particles being between 100 mm to 300 mm. Does the packedSiC spheres at the operating temperature of 900° C. act as a collectionof small waveguides which have dimensions below the cut off frequencyfor the applied electromagnetic radiation. If so, the susceptor'sstructure will not allow for the applied energy to penetrate into theentire volume of SiC granules. This type of structure would shieldelectromagnetic energy as exemplified in common practice by windows ofhousehold microwave cooking ovens. Or, does the packing of SiC spheresat an operating temperature of 900° C. have a finite depth ofpenetration which neither allows for the volumetric heating of theentire mass of SiC granules nor has electromagnetic energy throughoutthe volume of the SiC mass to interact with gaseous species for possibleenhanced reactions. This latter argument for a finite depth ofpenetration in this susceptor arrangement would most likely heat afinite volume of SiC granules near the surface of the incident appliedradiation, then heat would be thermally conducted through the SiC to theremaining volume of SiC granules since SiC in a very thermallyconductive material. One could argue that a greater power level ofapplied electromagnetic energy could be incident on the SiC granules ina attempt to heat the entire volume, however depth of penetration canbecome less at increased levels of applied power. The greater powerlevel will cause the depth of penetration to migrate to the surfacewhere the applied electromagnetic energy is initially incident upon,when the SiC material becomes more conductive at elevated temperature.The increased conductivity can cause the material to become reflectiveto the applied energy.

Other suscepting structures such as honeycombs, foams and wovenstructures can have similar concerns about the depth of penetrations asmentioned above. These structure, when made of semiconducting,conducting, ferromagnetic, ferrimagnetic, ferroelectric andanitferroelectric material, can have shallow depths of penetration.Graphite, carbon black, magnetite (Fe₃O₄), MnO₂ are materials that havedepths of penetration less than 1 mm at room temperature. Whensuscepting structures, such as honeycombs, foams and weaves are coatedwith these material, the structures will either have shallow penetrationdepths or act as waveguides that have dimensions which are below thecutoff frequency regardless of a) the bulk material or materials whichmakes up the substrate for the coating and b) the design of thesusceptor's structure. Consequently, a susceptor must be properlydesigns for volumetric interaction with the electromagnetic energy,taking into consideration the materials of construction, the structureand the effects of coatings.

SUMMARY OF INVENTION

This present invention, in its broadest sense, is to have an improvedesign which will produce a more homogeneous distribution of energyby 1) the design of the cavity geometry, 2) the location of the appliedenergy sources and 3) depth of penetration of the susceptor. The morehomogeneous distribution of energy in the susceptor will provide for theinvention to have the applied electromagnetic energy distributedvolumetrically to a) produce heat b) be present for interaction withchemical species for destruction of pollutants and to promote chemicalreaction throughout the susceptor c) to produce fluorescent radiationand d) to produce thermoluminescent radiation.

The cavity geometry can use polygons which have a cross-section that isirregular shaped, having four (4) more sides, preferably a rectanglewhere the cross-sectional areas of the rectangle is perpendicular to thedirection of flow of the gas stream. The preferred rectangle shape hasthe location of the applied energy source on opposing faces of thelongest parallel sides. The shortest distance of the irregular-shapedrectangular cross-section, which is referred to as the width. The widthis designed to promote a homogenous distribution of energy by design.This design is based upon the depth of penetration of the susceptor bythe applied electromagnetic energy. The depth of penetration of thesusceptor is used instead of the depth of penetration of a material,because the susceptor includes the void fraction, the material,materials or composite materials of construction and the susceptor'sstructure. The depth of penetration of the susceptor is define similarto the depth of penetration for a material as mentioned earlier as avalue of 1/e. The value of 1/e is equivalent to 67% of the energy beingabsorbed or scattered.

The cavity geometry together with the location of the applied energysources and depth of penetration of the susceptor play an important rolein the device. Since the energy sources are located on opposing faces ofthe irregular-shaped rectangle, the distance of one half the width,being the distance from the center of the cross-sectional area to theside of the cavity where the applied energy source is located, isdefined in this invention as the width of interaction. The width ofinteraction is similar to the depth of penetration. The width ofinteraction is used to bisect the susceptor in half to define the depthof penetration of the susceptor upon the half width of the cavity andthe susceptor's surface closest to the location of the applied energysources as described above. The width of interaction is used to describethe amount of energy that is available for interaction within thesusceptor to produce methods that promote chemical reaction anddestruction of pollutants, whereas commonly the depth of penetration ofelectromagnetic energy describes the about of power attenuated inmaterial. Attenuation can result in a material by a) absorption ofenergy to produce heat or b) reflection the applied energy. In thisinvention, the penetration depth of the susceptor can be use to providefor the destruction of pollutants or reaction of gases by either 1) amethod that primarily produces heat for thermal treatment, 2) a methodthat primarily uses the applied electromagnetic energy for interactionwith gaseous/particulate species for chemical reaction or destruction ofpollutants, 3) a method that produces fluorescent radiation, 4) a methodthat produces thermoluminescent radiation 5) a method that producesscattering of the applied electromagnetic energy for concentrating theapplied energy or 6) for a combination these five methods. Thecombination of the methods would be best suited for the purpose at hand.The following examples demonstrate these primary methods:

Example One: If thermal treatment is needed as the primary method forchemical reaction or destruction of pollutants, then adsorption ofelectromagnetic energy by the susceptor is needed to produce heat in therange for thermal incineration (600-1000° C.) or for catalytic treatment(300-600° C.). To produce volumetric heating in the susceptor by theapplied electromagnetic energy at the operating temperature, then theapplied energy must penetrate the entire width of interaction inside thecavity at the operating temperature. Therefore, the electromagneticenergy must be absorbed by the susceptor, and the depth of penetrationof the susceptor at the operating temperature must allow for the appliedelectromagnetic energy to volumetrically heat the width of interaction.For thermal treatment as primary method, where the shape of the cavityfor this device is an irregular-shaped polygon and the location of thesource of the applied electromagnetic energy is as mentioned above, thedepth of penetration of the susceptor should be approximately equivalentto one-third the entire width of susceptor. The depth of penetration ofthe susceptor being approximately ⅓ the width of the susceptor allowsfor approximately 50% of the total energy in the cavity from the sourcesof applied energy, which is located at opposing faces, to be present inthe width of interaction and to be absorbed by the susceptor's materialor materials of construction.

Example Two: If interaction of electromagnetic energy with the gaseousspecies is the primary method for treatment of the gases for chemicalreaction or destruction of the pollutants, then to produce volumetricinteraction of electromagnetic energy with the gaseous species theapplied energy must penetrated width of interaction inside the cavity atthe operating temperature. Therefore, the electromagnetic energy must beable to penetrate the susceptor, and the depth of penetration of thesusceptor at the operating temperature must allow for the appliedelectromagnetic energy to volumetrically interact with the gaseous orparticulate species for treatment in the width of interaction. In thismethod a susceptor may be used to produce turbulence so the gases canmix for better conversion of reactant species to product species. Forvolumetric interaction of electromagnetic energy with the gaseousspecies, where the shape of the cavity for this device is anirregular-shaped polygon and the location of the source of the appliedelectromagnetic energy is as mentioned above, the depth of penetrationof the susceptor is not as important for this method unless thesusceptor was design to scatter the applied electromagnetic energy. Thedepth of the penetration of the susceptor would be designed from amaterial or materials that are primarily transparent to the appliedelectromagnetic energy in order to maximize the amount of applied energyto be present to drive the reaction. Additionally, the susceptors coulduse field-concentrators to increase strength of the electromagneticenergy (The use of field-concentrators will be disclosed later in thissection). The depth of penetration of the susceptor for this method foreither reacting gases or destroying pollutants would be greater than theentire width of the susceptor and allow for approximately 50% of thetotal energy in the cavity from the sources of applied energy, which islocated at opposing faces, to be present in the width of interaction forinteraction between the applied energy and gaseous/particulate species.However, if scattering the applied energy is the desired for this methodof treatment, then the depth of penetration should be about ⅓ the widthof the susceptor.

Example Three: If a combination of treatment methods is needed as thebest method for either chemical reaction or destruction of pollutants,then adsorption, transmission, reflection and scattering ofelectromagnetic energy or energies by the susceptor may be required.Absorption of the applied electromagnetic energy in the susceptor couldeither produce heat, produce fluorescent radiation emissions,thermoluminescent radiation emissions or assist in producing fluorescentradiation. For example, an applied ultraviolet (UV) energy source can beused to produce phosphorescent radiation in a susceptor or at a fieldconcentrator for interaction between the phosphorescent radiation andthe gaseous/particulate species to drive the reaction. The applied UVenergy can also interact with the gaseous/particulate species. Such amaterial for the susceptor or field concentrator could be aphosphorescent material. The depth of penetration of susceptor mustallow for applied UV energy to penetrate the susceptor for volumetricinteraction a) with the susceptor to produce fluorescent radiationand/or b) direct interaction between the applied UV energy andgaseous/particulate species. Consequently, if UV and microwave energiesare applied to the same susceptor other interactions may occur betweenthe applied energies, material of construction of the susceptor, fieldconcentrators and the gaseous species (or particulate). The UV energywhich is applied to the cavity can interact as previously mentioned,however the microwave energy may a) produce thermoluminescence in thephosphoresent materials b) produce heat in the susceptor by the appliedmicrowave energy may enhance the phosphoresent radiation produceprimarily by the applied UV energy. Of other consequence, if the appliedenergy to the same susceptor is only microwave energy then otherinteractions may occur. The microwave energy may either a) be completelyabsorbed for thermal treatment of the gases, b) be partially absorbedand interact with the gaseous species for interaction, c) be used toheat the susceptor and produce thermophosphorescence of UV radiationwhich interacts with the gaseous species or d) a combination of thementioned interactions in a, b, and c.

This example, example three, demonstrates the potential complexity ofthe interaction of the applied electromagnetic energy, fluorescentradiation and thermoluminescent radiation with the susceptor's materialof construction and the susceptors construction. As previously mentionedin the Background section, the material or materials of construction aswell as the structure of the susceptor will influence the ability of theapplied electromagnetic energy or energies to penetrate and interactwith the susceptor a) to produce heat, b) be present for interactionwith the gaseous/particulate species, c) to produce fluorescence and d)to produce thermoluminesence. Likewise, the ability of fluorescent andthermoluminescent radiation to penetrate finite distances within thesusceptor's structure and interact with the gaseous/particulate speciesin the air stream for chemical reaction or destruction of pollutantscould be of importance to the design of the susceptor. Fluorescentradiation could be either phosphorescence, incandescence or fieldsgenerated by thermionic emissions or thermoelectricity emissions

In example three, the transmission of, absorption of, reflectivity ofand scattering of each wavelength of energy that is present in thesusceptor becomes important. Instead of the susceptor being constructedof a material, the susceptor may better be constructed of more than onematerial which will allow for the wavelength or wavelengths of theapplied electromagnetic energy or energies to penetrated andvolumetrically interact with the susceptor. And, the construction anddesign of the susceptor and the susceptor's materials of constructionwill have to be chosen to prevent the design of the susceptor'sstructure from shielding the wavelength or wavelengths of the appliedelectromagnetic energy and energies. And also, transmission, absorption,reflectivity and scattering properties of the susceptor will be effectedby the bulk density of the materials of construction, as well as theporosity size, pore structure and amount porosity in the materials ofconstruction

This invention, in its broadest sense, is an improve design which usescavity geometry that has a cross-section, which is perpendicular to theflow of the gas stream and is shaped as an irregular shaped, having four(4) more sides, preferably a rectangle. The preferred rectangle shapehas the location of the applied energy source on opposing faces of thelongest parallel sides of the cross-section area perpendicular to theflow of the gas stream. The location of the applied energy source andthe geometry of the cavity and susceptor does not allow for the opticalproperties of the device to concentrate energy, thus simplifying thedesign of a susceptor for interaction with the applied electromagneticenergy and producing a more homogeneous distribution of electromagneticenergy in the cavity. When the susceptor is designed for a specificmethod a treatment of the gas stream, the design will be only bedictated by the depth of penetration of the susceptor which is dependentupon the chosen width of interaction of the susceptor, since energy isnot concentrated. Therefore, once a method for treatment of the gasstream is chosen, once an amount of power of the applied electromagneticenergy or energies is chosen and once a width of interaction is decidedupon to reduce the static-pressure in the device, the susceptor'smaterials of construction and susceptor's structure can remain constantwhen the device is to be scaled for larger flow rates and larger exhaustduct width in commercial and industrial applications. To accommodatelarger flow rates or larger exhaust duct widths, only the length of thecross-sectional area of the irregular-shaped polygon where the energysource or sources are located can simply be elongated. Unlikecylindrical cavities, the absorption properties of the susceptor'smaterial or material of construction do not have be change toaccommodate greater flow rates and larger duct widths of commercial andindustrial process for volumetric heating or interaction of the appliedenergy with the gases inside the device susceptor.

With the design of the device in this invention, proper thermaltreatment of the pollutants can be achieve. Since this design simplifiesthe susceptor for producing heat at wide variety of flow rates and ductwidths, one can readily design devices for proper thermal treatment ofgases by selecting a operating temperature and by sizing length of a hotzone for the required residence time at the operating temperature andturbulence in the susceptor. Thermal insulation around the susceptor maybe needed to prevent heat losses. Material that is transparent to theapplied electromagnetic energy or energies and that uses an aerogelstructure would be best suited for thermal insulation. An aerogel is astructure which has over 96% porosity, a bulk density of 4%. The hotzone's length would be design in the coaxial direction of flow of theair stream where the direction is the defined breadth of the device.

In this broadest sense of the invention, the cavity's geometricalcross-sectional area perpendicular to the flow of the air stream and thesusceptor's width of interaction is designed to provide in this device amore homogenous distribution of energy with a given amount of appliedpower. With the more homogeneous distribution of energy, the inventionallow for one to design a method for specific treatment of gaseous andparticulate species, compared to designing treatment methods withdevices which have geometries that concentrate electromagnetic energysuch as a cylinder. With this invention, the depth of penetration of thesusceptor by the applied electromagnetic energy or energy allows one todesign methods of destroying pollution and reacting gases/particulatespecies. When the depth of the penetration of the susceptor is one third(⅓) the width of the susceptors total width or greater, the method oftreatment of gases/particulate can be either 1) primarily thermal, 2) acombination of thermal, fluorescent, thermoluminescent, and interactionbetween the applied energy or energies and the gas or particulate in theair stream, or 3) when scattering of the applied energy is used toconcentrated the applied energy without producing substantial heating ofsusceptor, such as a the low loss, low dielectric constant susceptorconstructed with metallic spheres and fused silica, the device canprimary treat by interaction between the applied energy or energies andthe gas or particulate in the air stream.

The design is improved over prior art because prior art used cylindricalgeometries. Cylindrical geometries tend to concentrate in a susceptor.Concentrated energy can lead to several problems when operating thedevice. One concern is the concentrated energy promote conditions thatlead to thermal runaway. The runaway can cause the susceptors materialor materials to melt, creating a pool of liquid material in thesusceptor. Another concern is that the concentrated energy will notallow the applied energy to volumetric heat a susceptor. Suchconcentration will require the absorbing properties of the susceptor'smaterial of construction to be graded to counter act the concentration,however this may not help. Also, susceptors in cylindrical cavities aremore difficult to scale up to greater flow rates and duct widths,because the absorption properties Another concern is that theconcentrated energy can lead to deleterious reaction between compositematerials and coatings on substrates. The deleterious reaction can causethe materials to melt at eutectic temperature, cause an article tobecome friable and alter the interaction between the appliedelectromagnetic material and the susceptor, changing the properties forsubsequent use.

Another aspect of this invention is a heat transfer process to increasethe efficiency of such devices which treat gases for chemical reactionor destruction of pollutants. Commercially available magnetrons aregenerally between 65-70% efficient. Therefore 30-35% of the energy thatis initially put into the system is lost. An aspect of this invention isa process for using that energy. In this heat transfer process, heat istransferred between heat energy that is produced by the tube or tubeswhich supplies the applied electromagnetic energy and air stream whichcontains the gases/particulates. The process of uses the heat from thetubes or tubes to preheat the air stream, or part of the air stream,prior to entering the device. This heat transfer process for preheatingthe air stream will decrease the cost of operating such a device. Theheat from the tube, or tubes, can be exchange with the air stream bysuch cooling fins that are found on commercial magnetrons, heat pipes,thermoelectric devices, cooling systems that circulate a fluid aroundthe tube-and release the heat at radiator. After the air stream ispreheated with heat from the tube, the air stream can be further heatedby heat transfer either a) from the cavity walls, b) from a conventionalheat exchanger (a recuperator) which is located after the exit end ofthe device or c) from both the cavity walls and conventionalrecuperator.

Another aspect of this invention is a susceptor design which isdescribed in this invention as a gas-permeable macroscopic artificialdielectric. The gas-permeable macroscopic artificial dielectricsusceptor device can be either a honeycomb structure, foam, or wovenfabric filter with a pattern, or a structure consisting of discretesusceptors. The macroscopic artificial dielectric susceptor can bedesigned a) for a specific cavity geometry, b) for a specific depth ofpenetration of applied and subsequent radiation produced from theapplied radiation, c) to be temperature self-limiting, d) to produce, inthe macroscopic artificial dielectric susceptor, a desired ratio of aself-limited temperature to power concentration of appliedelectromagnetic energy at one or more frequencies

This aspect of the invention distinguishes the term artificialdielectric by using an artificial dielectric material and a macroscopicartificial dielectric susceptor. An artificial dielectric material isused to describe the case where an article is constructed of compositematerial consisting of two or more materials each with differentdielectric properties, where one material is the matrix and the othermaterial is or other materials are embedded the matrix withoutsubstantial chemical reaction between the matrix and the embeddedmaterials. A macroscopic artificial dielectric susceptor is used todescribe a susceptor that is either a) an article constructed of amaterial where the article has a coating applied in a specific patternto create an artificial dielectric structure from the coating and thearticle b) a woven structure that contains two or more differentmaterials as threads (or yarns) which woven together to form anartificial dielectric structure or c) a structure that consists of amixture of discrete suscepting articles where the mixture containsdiscrete articles that have different dielectric properties and surroundeach other to form an artificial dielectric structure.

When the susceptor is a the gas-permeable macroscopic artificialdielectric structure which is a honeycomb structure constructed of amaterials, some of cell walls of the honeycomb can be coating withmaterials that have different dielectric properties to produce anmacroscopic artificial dielectric. The pattern of cells with coatedwalls are arranged in the honeycomb so that the applied electromagneticenergy and energies penetrate the suscepting structure and either heatthe susceptor or scatter the energy for interaction with thegases/particulate in the air stream. The pattern of the cell wallsattenuate the applied electromagnetic energy by either a) partially orcompletely by absorbing the applied energy, producing fluorescentradiation to heat the remaining parts of the susceptor and the airstream or b) partially or completely scattering applied energy toconcentrate the applied energy for interaction with the air stream or toheat the remaining volume of the susceptor. Also, a macroscopicartificial dielectric can be made from the honeycomb structure byfilling some of the cells with another material. Additionally, a largehoneycombed-shaped, macroscopic artificial dielectric structure can beconstructed from 1) smaller discrete susceptor articles that are smallhoneycombed shaped articles that have differing dielectric propertiesand/or conductivity or 2) smaller discrete susceptor articles that arehoneycombed shaped that have the same dielectric property and arecemented together with a material which has different dielectricproperties and/or conductivity. It is understood by one who reads this,that the same or similar methods use to create honeycombed-shapedmacroscopic artificial dielectrics can be employed to create macroscopicartificial dielectrics out of foams and weaves.

When the macroscopic artificial dielectric susceptor is designed asdevice with a structure consisting of discrete susceptors, susceptor canbe designed for complex interaction with the applied energy or energiesas previously described in Example 3. Potentially, each discretesusceptor can have separate characteristics for absorption,transmission, scattering and reflection of 1) applied electromagneticenergy or energies, 2) subsequent fluorescent radiation produced fromthe applied electromagnetic energy or energies and 3) the subsequentradiation from heat resulting from the dielectric loss within eachindividual susceptor. The discrete susceptors in this invention areknown as unit susceptors. The separate characteristics of absorption,transmission, scattering and reflection of a unit susceptor are effectedby the unit susceptor's length, thickness, shape, composite materialsstructure, material selection, porosity, pore sizes, temperaturedependence of the complex dielectric constant and thermal conductivity.

Since macroscopic artificial dielectric susceptors are made from amixture of unit susceptors, one is capable of designing a varietysusceptor structures. The versatility using unit susceptors will beapparent with the following discussion. Although the optical propertiesof each unit susceptor within the macroscopic artificial dielectric canbe independent, the structure of the macroscopic artificial dielectricsusceptor will dictate the interaction of the macroscopic susceptor withthe applied electromagnetic energy. The structure of the macroscopicartificial dielectric susceptor will be describe with the unitsusceptors that are primarily reflective. The reflectivity of the unitsusceptors can be produced from either metallic or intermetallicmaterials species at room temperature or materials such assemiconductors, ferroelectrics, ferromagnetics, antiferroelectrics, andantiferromagnetics which become reflective at elevated temperatures. Thematerials that produce reflection can be a) homogeneous b) a compositematerials having a second phase material in a matrix that is partiallyabsorptive to applied electromagnetic energy where he volume fraction ofthe second phase materials can be used to control the amount ofreflection of a unit susceptor or c) a coating on a unit susceptor.Also, the length, width and shape of the unit susceptors and thedistance between reflective unit susceptors can be controlled thereflectivity of the gas-permeable macroscopic susceptor.

The shape of the unit susceptor can be designed for reflection. Theshape of the unit susceptor can be either chiral, spirelike, helical,rod-like, ascicular, spherical, ellipsoidal, disc shaped, needle-like,plate-like, irregular-shaped or the shape of spaghetti twist in Muller'sSpaghetti and Creamette brand. The shape the unit susceptor can bedesign to produce turbulence in the air flow, thus provide for mixing ofreactants in the gaseous or liquid stream. The shape and size of thesusceptor can be used to grade the pore size of the susceptor toaccommodate the expansion of gas due to passing through the hot zone.

The temperature dependent materials that are used in unit susceptors canbe used to produce a temperature self-limiting macroscopic susceptor aswell as to produce in the macroscopic dielectric a desired ratio of aself-limited temperature to power concentration of appliedelectromagnetic energy at one or more frequencies. The above mentionedstructures can be produced and the desired effects achieved bycontrolling the volume fraction, size and shape of the unit susceptorsand the transmission, reflection, absorption and scattering produced bythe materials selection for each unit susceptor.

The macroscopic artificial dielectric susceptor works on the principleof reflection and diffuse reflection, scattering. The reflectivity ofthe macroscopic artificial dielectric susceptor is controlled be thevolume and interconnectivity of the unit susceptors which are theprimarily reflective unit susceptors in the macroscopic susceptor. Theprimarily reflective unit susceptors are defined as being the unitsusceptors to which are primarily reflective to the applied energy orenergies. The gas-permeable artificial dielectric susceptor has theprimarily reflective unit susceptors surrounded by unit susceptors thatare either primarily transparent or primarily absorptive of the appliedenergy or energies. As the volume of the primarily reflective unitsusceptors increases in the macroscopic susceptor, a degree ofinterconnectivity of the primarily reflective unit susceptor will occur,forming an interconnective network with in the macroscopic artificialsusceptor. The degree or amount of interconnectivity will depend on thesize and shape of the primarily reflective unit susceptors. The abilityof the applied energy or energies to penetrate the macroscopicartificial dielectric susceptor will depend not only on the volume ofthe primarily reflective unit susceptor but also on the degree andamount of interconnectivity. When the degree of interconnectivity of theprimarily reflective unit susceptors throughout the entire gas-permeablemacroscopic susceptor is such that maximum distance between theinterconnected network of the primarily reflective unit susceptors doesnot allow for applied energy to penetrate or the longest wavelength ofthe applied energies to penetrate, the gas-permeable macroscopicsusceptor, itself, will become primarily reflective to either a) theapplied electromagnetic energy or b) the longest wavelength of theapplied energies. In some instances, a high decree of interconnectivityis desired.

A high degree of interconnectiviy can be beneficial in some instances.Clusters of primarily reflective unit susceptors can be distributedabout the macroscopic artificial susceptor to promote scattering.Primarily reflective unit susceptors can be aggregated to form shapesand boundaries that reflect one or more wavelengths of the appliedenergy or energies. The volume fraction and interconnectivity of thereflective unit susceptors surrounding primarily absorbing or primarilytransparent unit susceptors can be used to design a) specificmacroscopic artificial dielectric structures for resonant cavities withthat are based upon the wavelength of the applied energy in thesusceptor, b) specific macroscopic artificial dielectric structures forscattering energy for interaction with gas or particulate species, c)specific macroscopic artificial dielectric structures that concentrateenergy at field concentrators which are located on other unitsusceptors, d) specific macroscopic artificial dielectric structureswhich concentrate energy within the susceptor for increase reactivitybetween the gas stream and the fluorescent radiation, e) specificmacroscopic artificial dielectric structures that have the primarilyreflective unit susceptors arranged in such a manner to produce a largespiral, helical or other shape with the macroscopic susceptor f)specific macroscopic artificial dielectric structures that as shieldingto prevent the applied electromagnetic from entering material inside thecavity for thermal insulation, g) specific macroscopic artificialdielectric structures that prevent leakage outside the cavity by theapplied energy, h) specific macroscopic artificial dielectric structuresthat reflect applied energy to other regions of the artificialdielectric to provide either higher temperatures or increased energy forreaction or destruction of gaseous/particulate species and i) possibly,specific macroscopic artificial dielectric structures that regulate thetemperature of the gas-stream.

The several benefits and advantages of this invention compared todevices of prior art will come apparent to one who reads the understandsthe following examples of this invention's emperical results. Table 1contains data from several gas-permeable macroscopic artificialdielectrics susceptors that were exposed to applied electromagneticenergy of a frequency of 2.45 Ghz in this invention's cavity asdescribed as having a rectangular cross-sectional area perpendicular tothe direction of the gas stream's flow. The location of the appliedenergy's source was as mentioned previously. Each of the followingexamples the gas-permeable, macroscopic artificial dielectric susceptoruses unit susceptors. A type-K thermocouple was inserted into the cavityafter the time show. Prior to inserting the thermocouple, all power tothe magnetrons was turned-off. In these examples, the unit susceptorsthat are designated as an aluminosilicate (AS) ceramic were made from a85/15 weight percent mixture of EPK Kaolin/KT Ball Clay. The unitsusceptor which are made of artificial dielectric materials have analuminosilicate matrix made from a 85/15 weight percent mixture of EPKKaolin/KT Ball Clay. The composition of the unit susceptors which aremade from artificial dielectric materials are designate by AS—(volumepercent of 2nd phase materials), i.e. AS-12 SiC. The particle size ofeach 2nd phase material was less then −325 US. mesh size. The “time toproduce a visible glow”—red heat—was observed visually. All exampleswere separate tests. The gas permeable macroscopic artificial dielectricsusceptor was exposed to approximately 12.6 KW of power from 16,800-wattmagnetrons. The dimensions of the cross-sectional area perpendicular todirection of flow was 7 inches in width and 14 inches in length. Thebreadth of the cavity was 22 inches. Eight magnetrons were located oneach side of the opposite sides of the largest parallel side of thecross-sectional area. On each side, the eight magnetrons were grouped inpairs, and the four pairs were group one after another along the breadthof the cavity. In these examples from experimental results, all unitsusceptors are shape as spaghetti twists (rotini). The spaghetti twistproduce a large amount of free volume with in the macroscopic artificialdielectric susceptor, over 70% free volume.

The result of experiments in these examples show the uniqueness of thisinvention, and the implications of these results that show severaladvantage over prior art will become clear to the reader afterunderstanding the discussion of the results.

Discussion 1: When the results of example 4 and 5 are compared, onefinds that the greater volume percentage of SiC, which makes anartificial dielectric material with in the unit susceptors, decreasesthe “time to show a red glow” and increases the temperature after onehour. The macroscopic susceptor of Example 4 is constructed of only unitsusceptors that have a composition of an aluminosilicate ceramic matrixcontaining 6 vol. % −325 mesh SiC, required 51 minutes to show “a redglow” and after one hour had a center temperature of 803° C., where asthe macroscopic susceptor of Example 5 is constructed of only unitsusceptors that have a composition of an aluminosilicate ceramic matrixcontaining 12 vol % −325 mesh SiC, required 27 minutes to show “a redglow” and after one hour had a center temperature of 858° C. Incomparing Example 4 with Example 5, one find that a greater percentageof SiC in the macroscopic susceptor produced a faster heating rate and ahigher temperature the macroscopic susceptor.

TABLE 1 Weight percentage of each unit susceptor Time to show aTemperature type in macroscopic red glow in the after one Examplesusceptor device hour Comments 4 100% AS-6 SiC 51 min 803° C. 5 100%AS-12 SiC 27 min 858° C. 6 100% AS 29 min >1260° C. the susceptor'stemperature exceed the limit of the type-K thermocouple 7 50% AS 36 min1006° C. 50% AS-12 SiC 8 50% AS 39 min 1008° C. temperature after 3hours 50% AS-12 SiC 9 50% AS 32 min 1006° C. temperature after 4 hourand 30 50% AS-12 SiC minutes 10  56% AS 6 min 1142° C. 23% AS-30 Cr₂O₃12% AS-30 Chromate 6% AS-30 Fe₂O₃ and Chromate 3% AS-30 Fe₂O₃ 11  18%AS-30 Chromate <2 min, then the had to 2 of the 16 magnetron tubes 19%AS-30 Cr₂O₃ glow shut melted from the back reflection 32% AS-30 Fe₂O₃/disappeared. down off the gas-permeable 30 Cr₂O₃ after 30 macroscopicsusceptor. Here 9% AS-30 Chomate/ minutes. the large volume and high 30Fe₂O₃ degree of interconnectivity 3% AS-30 Fe₂O₃ produced a veryreflective 19% AS-30 CaTiO₃ macroscpic susceptor.

Discussion 2: When the results of example 5 and 6 are compared, onefinds that the greater volume percentage of SiC, which makes anartificial dielectric material with in the unit susceptors, does notgreatly effect on the “time to show a red glow” and decreases thetemperature after one hour when compared to unit susceptors that arejust made from the aluminosilicate ceramic matrix material. Themacroscopic susceptor of Example 6 is constructed of only unitsusceptors that have a composition of an aluminosilicate ceramic matrixcontain 12 vol. % −325 mesh SiC, required 27 minutes to show “a redglow” and after one hour had a center temperature of 858° C., where asthe macroscopic susceptor of Example 6 is constructed of only unitsusceptors that have a composition of the an aluminosilicate ceramicmatrix contain 0 vol. % −325 mesh SiC, required 29 minutes to show “ared glow” and after one hour had a center temperature that was greaterthan 1260° C. In comparing Example 5 with Example 6, one finds that the12 vol. % of SiC in the macroscopic susceptor of Example 5 suppressesthe temperature of the macroscopic susceptor as compared to themacroscopic susceptor that was constructed of unit susceptors that areconstructed of the aluminosilicate matrix alone.

Comparsion between Discussion 1 with Discussion 2: In Discussion 1, theincreased volume percentage of SiC in the unit susceptors, that areconstructed of an artificial dielectric material, shows that the greatervolume of SiC in an artificial dielectric material increased theabsorption of the applied electromagnetic energy; The heating rate andtemperature after one hour increased. In Discussion 2, the resultsshowed that the macroscopic susceptor with without the artificialdielectric material, (AS-vol. % SiC), had a) about the same heating rateas the artificial dielectric material with 12 vol. % SiC and b) a highertemperature than the artificial dielectric material with 12 vol. % SiC.One can understand that the greater SiC content in the artificialmaterial in Example 5 compared to Example 4, increase the absorption ofmacroscopic susceptors.

One can also understand that when one compares Example 5 to Example 6,one finds that the absorption of the applied energy by the unitsusceptor which are made of an artificial dielectric material suppressesthe temperature after one hour. This suppression of the temperature canbe due to the reflectivity of the SiC as the temperature of the SiCincreases.

Discussion 3: When one compares Example 7 with Example 4, one findintriguing results. Example 7 uses a macroscopic artificial dielectricsusceptor made from a 50/50 mixture of two types of unit susceptors. Onetype of unit susceptor is the primarily reflective and is constructed ofan artificial dielectric material, AS-12 SiC, the material used inexample 5. The other type of unit susceptors is the primarily absorptiveunit susceptor material and is construction of the AS material that wasused in Example 6. The 50/50 mixture of the two types of unit susceptorsdid not produce an interconnective network between the primarilyreflective unit susceptors. When one carefully compares the results fromexample 4 and example 7, one finds that the total amount of SiC on themacroscopic susceptor for the unit susceptor that are constructed of theartificial material, AS-6SiC in example 4 is approximately equal to thetotal volume of SiC in the macroscopic artificial dielectric susceptorin Example 7. In Example 7, the 50/50 mixture of the AS unit susceptorsand the AS-12 vol. % unit susceptors produces approximately the samevolume of SiC in the macroscopic susceptor as Example 4. However,Example 7 has faster “time to show a red glow” then Example 4 and ahigher temperature after one hour (1006° C.). One can that absorption bythe total volume of SiC in the macroscopic susceptor cannot be fullyresponsible for the results in Example 7. It is the structure, themacroscopic artificial dielectric susceptor that is responsible for theincrease time “to show a red glow” and a higher temperature after onehour (1006° C.). Therefore, the structure of the macroscopic artificialdielectric susceptor, that contains the primarily reflective unitsusceptors that are mixed with the primarily absorptive susceptors, mustbe having the primarily reflective unit susceptors reflecting, orscattering the applied energy and, the scattered (reflected) energy isbeing absorbed by the primarily absorptive unit susceptors. Theprimarily reflective unit susceptors are concentrating the energy withinthe macroscopic artificial dielectric susceptor.

Discussion 4: When one compares the results from Examples 7,8 and 9, onefinds that the macroscopic artificial dielectric structure can produce aself-limiting temperature, and since it can produce a self-limitingtemperature, the gas-permeable macroscopic artificial dielectricstructure should allow one to design macroscopic artificial dielectricstructures to a desired self-limiting temperature to power concentrationof applied energy or energies to beat gases, treat pollutants in a gasstream and to react chemical species in a gas stream.

Discussion 5: The results of Example 10 show an effect one finds whenthe gas-permeable macroscopic artificial dielectric susceptor isconstruct of primarily reflective unit susceptors which are made from anartificial dielectric material than contains a greater volume percentageof semi-conducting and a materials with a Curie temperature. The primaryreflective unit susceptors were constructed of an artificial dielectriccontaining 30 vol. % of −325 mesh materials that were either Cr₂O₃,Fe₂O₃, chromate or a mixture contain two of the three naterial. Thematrix of the artificial dielectric material was the AS materials. Thegas-permeable artificial dielectric that was constructed from was theseprimarily reflective unit susceptors, had a very fast time “to show ared glow” and a high temperature (1142° C.). Example 10 shows that theamount of reflection of the primarily reflective susceptors influencesthe heat rate of, temperature of and energy concentration within themacroscopic artificial dielectric susceptor. One can understand thatamount of reflection also should allow one to design macroscopicartificial dielectric structures to a desired self-limiting temperatureto power concentration of applied energy or energies to heat gases,treat pollutants in a gas stream and to react chemical species in a gasstream as well will increase the energy concentration within theartificial dielectric susceptor.

Discussion 6: Example 11 exemplifies what happens when the volumefraction and the interconnectivity of the primarily unit reflectivesusceptors become too great. At first one sees that a very fast time “toshow a red glow red” is present, then the glow disappears. What hashappened in this example is that the temperature of the primarilyreflective unit susceptors increased by absorbing the applied energy,and then the increased temperature caused the primarily reflective unitsusceptors either to have Curie temperature to be exceeded, to havegreater reflectivity or both in the unit susceptors' materials ofconstruction. With the increase reflectivity, Curie temperatureexceeded, high volume fraction of the primarily reflective unitsusceptor and extremely high degree the interconnectivity of theprimarily reflective unit susceptors, the macroscopic artificialdielectric susceptor became reflective and did not allow for the appliedenergy to volumetrically interact with the macroscopic artificialdielectric susceptor. The back reflection from the macroscopicartificial dielectric susceptor destroyed two microwave tubes.

Of importance is the structure of a macroscopic artificial dielectricsusceptor. The structure should allows for applied electromagneticenergy to penetrate the distance between the primarily reflectivecomponents, whether a discrete susceptor, coating or woven structure sothe structure does not act as a collection of waveguides with cut-offfrequencies that prevent the applied energy from penetrating the widthof interaction.

Another aspect of this invention is the use of the structure of themacroscopic artificial dielectric susceptor for adsorption, regenerationand desorption of gaseous reactants or pollutants. The structure can beused such devices as is known in the field of pollution control deviceas rotary concentrators or other devices that use adsorption in aprocess to treat to pollutants. Typically In such devices, a zeolitematerials or activated carbon is used to adsorb gaseous species. Otherforms are carbon can be used, also. The penetration depth of carbon inthe form of an article tends to be about one micron, and in loosepowder, the penetration depth can be 3 mm. Zeolite materials, dependingupon their doping, have much greater penetration depths. A macroscopicartificial dielectric susceptor can be made from a mixture of unitsusceptors. The mixture would contain unit susceptor made with activatedcarbon and unit susceptors made with zeolites. Also, unit susceptors canbe made from either a) artificial dielectric materials having a zeoliteas the matrix and a carbon species as the second phase, b) artificialdielectric materials having a carbon species as the matrix and zeolitesspecies as the second phase or c) unit susceptors that are coating witha carbon species, preferably activated carbon. As in the keeping withthe aspects of this invention, the structure of a macroscopic artificialdielectric susceptor should allows for applied electromagnetic energy topenetrate the distance between the primarily reflective components,whether a discrete susceptor, coating or woven structure so that thestructure does not act as a collection of waveguides with cut-offfrequencies that prevent the applied energy from penetrating the widthof interaction. Another aspect of this invention is the use ofsemi-conducting metals and ceramics, ionic-conducting ceramics,ferromagnetic, ferrimagnetic, ferroelectric and antiferroelectricmaterial for their reflective characteristics materials with the appliedelectromagnetic energy. These types of materials tends to primarilyabsorbing materials as articles or large particles (particle sizesgreater than 250 microns), however when the particles size of thesetypes of materials are 50 microns or less these semi-conducing materialsgreatly absorb the applied energy, especially wavelengths in themicrowave region, and reach very high temperatures, becoming veryconductive. When these materials become very conductive at hightemperatures, they become very reflective. Reflective Behavior from thesmall particle-size SiC in the unit susceptors that had were constructedof artificial dielectric materials, not the volume fraction of the SiC,is the only way to explain the different behavior between Example 4,Example 5 and Example 7. In this invention, SiC is used as a hightemperature reflector.

The conductivity of this of type materials as well as other ceramicmaterials, mentioned above can be controlled by cation and anionsubstitution on the lattice structure of a materials. Typically, theamount of substitution on cation or anion on a lattice structure of amaterial would be less than 15 mole percent.

The absorption, transmission, reflection, scattering and the complexdielectric constant of unit susceptors can be controlled by usingcomposite materials. These composite materials is artificialdielectrics, layered or coated composites, have a matrix materialcontaining a second phase or third phase which have a particle diameterless than −325 US mesh size. The composite materials for unit susceptorscan use combination of materials in such a fashion where the matrix isa) a metal forming a cermet, b) polymeric organic materials, c) apolycrystalline ceramic, d) a glass/ceramic material and e)intermetallic. Materials for the matrix, substrate for a coated unitsusceptor or entire unit susceptor include a) aluminosilicates andsilica derived from clays or mixture of clays, b) alumina, c) MgO d)stabilized and partially stabilized zirconia, e) magnesium silicates andsilica derive from talcs, f) enstatite g) forsterite, h) steatite, i)porcelain ceramics, j) cordiertie, k) fused silica l) stainless steeland m) cast iron. The second phase materials can be 1) athermoluminescent material, 2) a phosphoresent material, 3) anincandescent material 4) ferroelectric, 5) ferromagnetic, 6)ferrimagnetic, 7) MnO₂, 8) TiO₂, 9) CuO, 10) NiO, 11) Fe₂O₃, 12) Cr₂O₃,13) Li₂O doped MnO₂, 14) Li₂O doped CuO, 15) Li₂O doped NiO 16)CuO—MnO₂—Li₂O complex 17) CuO—MnO₂ 18) silicide, 19) borides, 20)aluminides, 21) nitrides, 22) carbides, 23) ceramic glazes with metalparticles, and 24) ceramic glazes with semi-conducting particles. Theshape of the second phase materials can be chiral, spirelike, helical,rod-like, ascicular, spherical, ellipsoidal, disc shaped,irregular-shape, plate-like or needle-like.

Another aspect of this invention is conceptual design of the structureof a a unit susceptors artificial dielectric material that increases thechemical compatibility between the matrix and 2nd phase material. Thesize of the 2nd phase material can be used to control the chemicalcompatibility between the matrix and the 2nd phase material. Largerparticle sizes of the second phase material will make the second phasematerials more compatible with the matrix. In this invention, where thesecond phase material has questionable compatibility with the matrix thesecond phase material is to have a particle size between 200 microns and4 mm. Chemical incompatibility can lend to melting or other solid-statereactions at the interface between the matrix and the second phasematerial. The melting and solid-state reactions can lead to greaterabsorption, and possible to a situation that leads to thermal runaway inthe material.

Another aspect of this invention is the design of unit susceptors thathave artificial dielectric materials that have a compatible thermalexpansions between the matrix and the 2nd phase material. Poor thermalexpansion compatibility can lead to friable unit susceptors fromthermally cycling the device during operation. The two methods that thisdevice uses are a) materials where the thermal expansion mismatch isless than 15% and b) the matrix and the 2nd phase material has the samelattice structure and principle composition, but the lattice structureof the second phase material is doped with a cation or an anion tochange the electrical resistivity of the 2nd phase material in theartificial dielectric material. Using the spinel structure as examples,the matrix material can be MgAl₂O₄ and the second phase material wouldbe (Mg,Fe)Al₂O₄, and matrix of Fe₂O₃ and the 2nd phase material is Fe₂O₃doped the TiO₂. Additionally, the matrix can be AlN and the second phasematerials can be AlN dope with Fe⁺³.

The thermal conductivity of the unit susceptor can be controlled forheat transfer. The thermal conductivity can be controlled by either a)porosity of the material of the unit susceptor, b) the compositestructure of the unit susceptor, c) high thermally conductive materialssuch as from high purtiy nitrides, aluminides, suicides, borides andcarbides d) highly thermally conductive coatings can be used as coatingon porous unit susceptors to increase the thermal conductivity at thesurface or e) grading the pore structure by flame polishing the outersurface of the susceptor.

Another aspect of this invention is the use of unit susceptors orcoatings on unit susceptors that are sacrificial. The sacrificialsusceptors or coatings are used in either in chemical reactions or usedto treat pollutants. For example, to eliminate NO_(x) from polluted gasstreams NO_(x) can be reacted with carbon to produce N₂ and CO₂. In thisexample carbon is needed as a reactant. Therefore, unit susceptors orcoating on unit susceptors could be made with carbon that issacrificial. After the carbon-containing unit susceptor are used up, themacroscopic artificial dielectric structure can be replenished with thenew carbon-containing susceptors. The form of carbon can be activatedcarbon, carbon black, soot, pitch or graphite.

Another aspect of this invention is the use of field concentrators onthe surface of the unit susceptors. The field concentrators concentratethe electromagnetic locally so a high intensity electromagnetic field isavailable to interact with gaseous/particulate species to either drivechemical reaction, enhance the reaction between chemical species or totreat pollutants. The field concentrator would be made from either a)conductors, b) semi-conductors, c) materials with a Curie Point, d)ionic-conducting ceramic, e) a composite materials from a and c, f) acomposite materials form b and c, g) composite materials from a and dand h) composite materials from b and d. The shape of the compositematerials can be either chiral, spirelike, helical, rod-like, ascicular,spherical, ellipsoidal, disc shaped, irregular-shape, platelike,needle-like or have a shape that has sharp-pointed-gear-like teeth. Thesize of the field concentrators can be one to 10 times the depth ofpenetration of applied electromagnetic energy of material construction,either at room temperature or the operating temperature. This sizedifference depends on the chemical compatibility between the fieldconcentrators and the unit susceptor's materials of construction. Wherethere is little concern for deleterious reaction between the unitsusceptor and field concentrator, then the size of the fieldconcentrator, which, based on it's depth of penetration of the materialsof construction, can be 1 to 10 times the depth penetration at theoperating temperature. If there is great concern for deleteriousreaction between the unit susceptor and field concentrator, then thesize of the field concentrator should be such not to promote reaction,200 microns to 4 mm. Additionally a barrier coating between the fieldconcentrator and the unit susceptor can be present to preventdeleterious chemical reaction between the field concentrator and theunit susceptor. Materials for field concentrators include materials thatcan be 1) a thermoluminescent material, 2) a phosphoresent material, 3)an incandescent material 4) ferroelectric, 5) ferromagnetic, 6)ferrimagnetic, 7) MnO₂, 8) TiO₂, 9) CuO, 10) NiO, 11) Fe₂O₃, 12) Cr₂O₃,13) Li₂O doped MnO₂, 14) Li₂O doped CuO, 15) Li₂O doped NiO 16)CuO—MnO₂—Li₂O complex 17) CuO—MnO₂ 18) silicide, 19) borides, 20)aluminides, 21) nitrides, 22) carbides, 23) ceramic glazes with metalparticles, 24) ceramic glazes with semiconducting particles, 25)materials that produce thermionic emissions and 26) thermoelectricmaterials.

Another aspect of this invention is the production of ozone from unitsusceptors and field concentrators. When the distance (gap) between twoconducting or semiconducting field concentrator become close enough tocause a discharge of a spark for the field that are produced by theapplied electromagnetic energy, and ozone will be produced. The sametype of discharge can occur on the surface of unit susceptors that areconstructed of an artificial dielectric material. A spark can occur fromgap between the exposed surfaces of the 2nd phase material in theartificial dielectric, and ozone can be produce. This can occur atelevated temperature and when the volume fraction of the 2nd phasematerial exceeds twenty percent (20%). Also, an electric discharge canoccur between two unit susceptors that contain field concentrators andthe gap between exposed surfaces of 2nd phase material from two unitsusceptors.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1. A cross-section of the device according to the inventions in anlongitual axial direction of the breadth of the device and width of thedevice.

FIG. 2. The device as in FIG. 1 with thermally insulating layers

FIG. 3. The cross-section of the device which is normal to the directionof Flow with relationship between the susceptor,9, and the to the depthof penetration of the susceptor, 14.

FIG. 4 A Flow Chart Represent a Heat Transfer Process

FIG. 5 A 2-Dimensional Graphical Representation of the Gas-Permeable,Macroscopic Artificial Dielectric Susceptor which is Constructed ofObjects Representing Unit Susceptors where One Type of Unit Susceptor isPrimarily Reflect and the Other Type of unit Susceptor is eitherPrimarily Transparent or Partially Absorptive.

FIG. 6. A 2-Dimensional Graphical Representation of the Gas-Permeable,Macroscopic Artificial Dielectric Susceptor which is Constructed ofObjects Representing Unit Susceptors that have for an InterconnectedNetwork of Primarily Reflective Unit Susceptors.

FIG. 7. A Unit Susceptor that is Constructed of an artificial dielectricmaterial.

FIG. 8. Field Concentrators on the Unit Susceptors

DETAILED DESCRIPTION OF INVENTION

This invention is a device which uses a gas-permeable structure for asusceptor of electromagnetic energy to react gases for desired productsor to treat pollutants for producing clean air which can be dischargeinto the environment in accordance with the law of the land. The devicehas a specific cavity geometry, location where the of the applied energyfrom a source enters the cavity, a susceptor that is designed by thedepth of penetration of the susceptor, and a means to scale-up thedevice for larger flow rates of an air stream without changing thesusceptor's interaction with the applied energy or depth of penetrationof the susceptor because the device is designed to increase the size ofthe device by a near linear scale from the location of the where theapplied electromagnetic energy enters the cavity and the cavity'sgeometry.

Another aspect of this invention is a heat transfer process thatincreases the efficiency of the device.

Another aspect of this invention is a gas-permeable, macroscopicartificial dielectric susceptor which uses reflection, scattering andconcentration of the applied electromagnetic energy which is used a) toreact gases for desired products or to treat pollutants for producingclean air which can be discharge into the environment in accordance withthe law of the land, b) to regulated the temperature of the air stream,c) prevent the device from overheating, d) to prevent deleteriousreactions between the materials of construction, e) to heat a gasstream, f) to create a device of substantial size for adsorption andregeneration of gaseous species from a mixture of carbon-containingsusceptor and zeolite-containing susceptors and g) to produce a desiredratio of a self-limited temperature to power concentration of appliedenergy or energies to perform the desired utility.

Another aspect of this invention is the structure of the unit susceptorswhich can make up the gas-permeable, macroscopic artificial dielectricsusceptor.

Another aspect of this invention is the use of field concentrators onunit susceptors to create local electromagnetic fields by interactionwith the applied electromagnetic energy.

The integral parts of the device are the cavity, 1, the inlet opening,2, which is permeable to gases and particulate and provides a means toprevent applied electromagnetic energy from escaping the cavity, theoutlet opening, 3, which is permeable to gases and provides a means toprevent applied electromagnetic energy from escaping the cavity, openingto the cavity, 4, which allows the applied electromagnetic energy toenter the cavity, lenses, 5, which focus or disperses the appliedelectromagnetic energy in the cavity, and if necessary, provides agas-tight seal to prevent gases and particulate from escaping thecavity, applied energy, 6, electromagnetic energy sources, 7,waveguides, 8, and susceptor, 9, which is the suscepting region on thedevice.

Discussion of FIGS. 1, 2 and 3 illustrates the construction of thedevice to react gases for desired products or to treat pollutants forproducing clean air which can be discharge into the environment inaccordance with the law of the land, details the operation for thedevice and discloses, in its broadest sense, the primary embodiment ofthis invention.

FIG. 1 is an axial, longitudinal section of the device which is known asin this invention as the device breadth. In FIG. 1, the geometric axesof the device are given by arrows marked W for width and B for breadth.The device has a rectangular cavity, 1, having an inlet opening, 2,where reactant gases or pollutants enter the cavity. Inlet opening to isdesigned the be permeable to reactant gases, pollutants and particulatein the air stream. The reactant gases, pollutants and particulate entercavity, 1, thought inlet, 2, and enter susceptor, 9. As the reactantgases, pollutants and particulate pass through susceptor, 9, eithergaseous reactants are convert to products or pollutants and particulatesare converted to clean air which can be discharged into the environmentin accordance with the law of the land by the necessary treatment meanswhich are produced from the interaction of applied electromagneticenergy, 6 with susceptor, 9. The products and clean air exit cavity, 1,though outlet opening, 3. The interaction between applied energy, 6 andsusceptor 9 can provide treatment means either a) by a primarily thermalmethod having all or a very large amount the applied electromagneticenergy, 6, being absorbed and producing heat in susceptor, 9, b) by amethod having the electromagnetic energy primarily interacts with thegas reactants, pollutants and particulates without a substantialquantity of applied energy, 6, absorbed by susceptor, 9, producing heat,c) by method having a combination of methods a and b, or d) by a methodwhere the combine effects of method c and other subsequent fluorescentradiation, thermoluminescent radiation, thermionic emission andthermoelectricity assist in treating the gas reactants, pollutants andparticulates. The method of treatment is determined by the interactionof applied electromagnetic energy, 6, with the material or materials ofconstruction that make-up the susceptor, 9. The applied electromagneticenergy, 6, can be of more than one frequency, UV, IR, visible andmicrowave The applied electromagnetic energy, 6, enters cavity, 1,through openings, 4, that are located on opposing sides of the cavity,1, as shown in FIGS. 1, 2 and 3. The applied electromagnetic energy, 6,is generated from electromagnetic sources, 7, travels down waveguides,8, and can pass through lenses, 5, which can be located at cavityopening, 4, then interacts with the susceptor, 9. If lenses, 5, are notneed for the operating conditions of the device, then the appliedelectromagnetic energy, 6, can just enter cavity, 1, through cavityopenings 4. The reactant gases, pollutants and particulates enterthrough inlet opening, 2, enter susceptor, 9, for treatment Turbulencecan be generated by the structure of susceptor, 9, to provide bettermixing. The residence time in the device that is required by a specifictreatment method is provided increasing the breadth of the device, whichis inclusive of increasing the breadth of susceptor, 9, and cavity, 1.Additionally energy sources, 7, waveguides, 8, and cavity openings, 4,can be arranged along the breadth of the device to provide the necessarypower of applied energy to the susceptor for treatment. Suchadditionally energy sources ,7, waveguides, 8, and cavity openings onopposing faces can be arranged by anyone skilled in the art to providethe optimum conditions. Electronic method of controlling applied powerand start-up methods can be employ by those skill in the art withouttaking away from the embodiment of this invention. This device can beemployed in operation in a horizontal position a vertical position.

FIG. 2 provide the same view as FIG. 1. FIG. 2 illustrates the locationof thermal insulation, 10, and a in thermally insulating barrier, 11,that prevents gases, pollutants and particulates from passing throughits boundaries. Thermal insulation, 10, and a thin thermally insulatingbarrier, 11, surround the perimeter of susceptor, 9, in the direction ofthe breadth of the susceptor. Thermal insulation, 10, and thin thermallyinsulating barrier, 11, is constructed of material that is transparentto the applied electromagnetic energy. Material of construction that aretransparent to the applied electromagnetic energy can be high purityalumina, aluminosilicate, MgO, steatite, enstatite, fosterite, nitrides,ceramic porcelain, fused silicate and glass in fiber or foam form. Thepreferred materials structure for thermal insulation, 10, is an aerogel.The thermally insulating layer, 10, and thin thermally insulatingbarrier, 11, are employed to prevent cavity, 1, and waveguides, 8, andenergy sources, 7, from being effected in an adverse manner by heat fromtreatment methods which can cause unwanted thermal expansion, corrosionand deterioration of electronic.

FIG. 3 is a cross-section of the device that is normal to the directionof gas flow from inlet, 2, to outlet, 3. The directional axes for thediscussion of the embodiments of the device are show in FIG. 3 andlabeled W for width and L for length. The device in this inventionembodies the geometric shape of the cavity's cross-section that isnormal to the direction of airflow, 14, in cavity, 1, the location ofopenings, 4, in cavity, 1, the depth of penetration of the susceptor,13, and the width of interaction, 12. The geometric shape of thecavity's cross-section that is normal to the direction of flow, 14, isan irregular shaped polygon that has the largest dimension of the twoparallel sides as it length. There preferred irregular-polygon has four(4) sides and is a rectangle as shown in FIG. 3. This embodiment is notlimit to a irregular-shaped polygon with 4 side, the irregular-shapedpolygon must have a minimum of four (4) sides. This invention embodiesthe geometric shape of the susceptor's cross-sectional area that isnormal to the direction of flow of susceptor, 9, to have the samegeometric shape of the cavity's cross-sectional area that is normal tothe direction of flow, 14. The is invention embodies the location of theopenings, 4, in cavity, 1, to be located on opposing sides of longestparallel direction of the cavity cross-section that is normal to thedirection of flow, 14, which is termed the length of cross-section, 14.

The susceptor, 9, in this invention embodies a design to have volumetricinteraction with the electromagnetic energy. Susceptor, 9, is designedto have a depth of penetration of the susceptor, 13, by appliedelectromagnetic energy, 6, at the operating temperature that can not beless then one-third (⅓) the width of the of susceptor. This embodieddesign allows for a minimum 50% of the applied electromagnetic energy,6, to be present in each half volume of the susceptor, 9, where the halfvolume of the susceptor is defined by the product of width ofinteraction, 12, by the length of the susceptor by the breadth of thesusceptor. The width of interaction is equal to the one-half of thewidth of the interior dimensions of cavity, 1. The embodied susceptordesign allows a) for volumetric interaction between the applied energy,6, and the susceptor, 9 and b) for volumetric interaction betweenapplied energy, 6, and the reactant gases, pollutants and particulates.The rectangular cavity design does not concentrated energy by thegeometry of the rectangular cavity, 1, or the rectangular shape of thesusceptor. Provided that the susceptor is a homogeneous material, therectangular shape of the susceptor interacts optically with the appliedelectromagnetic energy, 6, from openings, 4, in cavity, 1, as though thesusceptor was a flat lens. On the other hand, if the geometry of thecavity's cross-sectional area normal to the direction of flow andgeometry of the susceptor's cross-sectional area normal to the directionof flow was circular and the applied energy enters this type of cavityfrom openings that were located around the perimeter of the cavity, thenapplied energy will tend to concentrate in the circular susceptor. Thedevice, in this invention, embodies the ability to linearly scale thedevice for gas streams with larger flow rates without having to redesignthe depth of penetration of the susceptor, 13. The linear scale isaccomplished simply by keeping the widths of susceptor, 9, and ofcavity, 1 while extending the lengths of the susceptor, 9, and cavity 1.The depth of penetration of the susceptor, 13, and the width ofinteraction, 12, will remain constant. One may have to add more energysources , 7, waveguides, 8, openings, 4, in cavity, 1, along theextended length to provide more power to the cavity, but the costinvolve is much less then redesigning the susceptor's properties thatinteract with the applied electromagnetic energy to provide volumetricinteraction with between the applied energy and the susceptor's andcavity's new size and geometric structure. Additionally, the cost totreat higher flow rates in the same size cavity as lower flow rates byincreases the power can require the use of costly high power tubes thatproduce the electromagnetic energy. Another aspect of the invention, asshown in FIG. 3, is employing waveguides, 8, that intersect the surfacesof the cavity, 1, at oblique angles to produce large openings, 4, incavity, 1, that allows for the applied electromagnetic energy, 4, to beapplied over a larger surface of the susceptor. Also, the use ofwaveguides, 8, allows for the energy source, 7, to be located away forthe cavity to lessen any deleterious interaction between heat and theenergy source, 7.

The dimensions of the cavity, 1, can be designed for the frequency ofthe applied electromagnetic energy and the TE and TM modes of theapplied electromagnetic energy. The size of the cavity may be adjustedto accommodate desired TE and TM modes at certain power levels whichproduce more uniform heating of the susceptor.

The inlet, 2, and outlet, 3, can prevent the applied electromagneticenergy, 6, from escaping with a perforated article made from areflective artificial dielectric materials, polarizers that are arrangedin a ‘cross-nickles’ fashion, fermi-cages, attenuators, or undulatingpaths.

The thickness of the wall in cavity, 1, is determined by the skin depthof the material for the applied frequency or frequencies. The thicknessof the wall is a minimum three (3) skin depths of the material for theapplied frequency. When more than one frequency of electromagneticenergy is applied to the cavity, the skin depth of materials isdetermined by the lowest frequency of radiation.

The material of construction which are selected for the cavity, 1, isdependent on operating temperatures. The materials can be stainlesssteels, aluminum, aluminum alloy, nickel, nickel alloy, inconel,tungsten, tungsten alloys, aluminides, silicides, vanadium alloys,ferritic steel, graphite, molybdenum, titanium, titanium alloys,artificial dielectric materials which are design to reflect incidentradiation, copper alloys, niobium alloys, chromium alloy, inconel,chromel, alumel, copper/constantine alloys and other high temperaturealloys. For radio frequencies, transparent materials such as aluminaporcelains, zircon porcelains, lithia porcelains, high temperatureporcelains, glasses, alumina, mullite, fused silica, quartz, forsterite,steatite, cordierite, enstatite, BN, AlN, Si₃N₄, oxides and otherpolymers which exhibit low dielectric and conductive losses at theapplied frequencies can be applied.

The applied electromagnetic energy at one or more frequencies can enterthe cavity through openings, 4, in the walls adjacent to the macroscopicsusceptor or be channeled through the cavity to the macroscopicsusceptor from either above, below or passing through transparentthermal insulation adjacent to the side walls. The applied energy canenter through a single or plural openings that either contain insertedbulbs, antenna or tubes, that are either couplers, lenses, slottedwaveguide or zig-zag slotted waveguides. The applied energy, 6, can belinearly polarized, circularly polarized or polarized by reflection orscattering. Entering radiation from multiple couple can be polarized insuch a manner at to achieve a better distribution of electromagneticenergy in the cavity.

More than one frequency of electromagnetic energy can be propagatedthrough the openings, 4. For waveguides, 8, the cut-off frequency willdetermine the frequencies which can propagate through the waveguide.

When lenses, 5, are employed, optical engineering for the lenses can beused to obtain the desired effect. The radius of curvature of the lensor lenses can be adjusted to concentrate or disperse the electromagneticenergy (convergence and divergence of the applied energy). The lensthickness can be adjust to eliminate or greatly reduce reflection of theenergy so that the reflection of the energy back to the radiation sourcedoes not damage the source. Coatings on the lenses can be use to reflectselected wavelengths back into the cavity. Materials for lenses, 5,should have high purity (greater than 99% pure) transparent singlecrystals, polycrystalline and amorphous organic and inorganic materialswith low dielectric constants, low dielectric losses such as such asalumina porcelains, zircon porcelains, lithia porcelains, hightemperature porcelains, glasses, alumina, mullite, forsterite, steatite,cordierite, enstatite, BN, AlN, Si3N4,oxides and other polymers, MgO,fused silica, iodides, bromides, polycarbonate, polypropolyne, quartz.The porosity of the material can be use to scatter the applied energyinto the cavity. The porosity would be designed for the applied energy.

Waveguides, 8, can be either horns or be rectangular, cylindrical,parabolic shape. The best waveguide shape is a rectangle that interceptthe surface of the cavity at oblique angles as shown in FIG. 3. Theoblique angle increases cross-sectional area of the opening into thecavity and minimized the back reflection off the surface of themacroscopic susceptor and/or insulation into the waveguide which wouldbe transmitted back to the radiation source, 7, or diminish the power,6, emanating from the waveguides, 8.

Another embodiment of this invention is a heat transfer process. Theheat transfer process is illustrated by the flow chart in FIG. 4. Theinvention embodies the input gases obtaining heat, or being preheated,prior to entering the device for thermal or other methods of treatmentby a heat exchange method that provides heat to the input gases fromheat that is produced from the source for applied energy. The source canbe a magnetron, a UV lamp, an IR lamp or other electronic device thatproduce the applied energy, 6. Such device generally operate a lowefficiencies and produce heat. This heat transfer process for preheatingthe air stream will decrease the cost of operating such a device. Theheat from the tube, or tubes, can be exchange with the air stream bysuch cooling fins, such a those that are found on commercial magnetrons,heat pipes, thermoelectric devices, cooling systems that circulate afluid around the tube or lamp and release the heat at radiator. Afterthe air stream is preheated with heat from the tube, the air stream canbe further heated by heat transfer either a) from the cavity walls, b)from a conventional heat exchanger (a recuperator) which is locatedafter the exit end of the device or c) from both the cavity walls andconventional recuperator.

Another embodiment of this invention is a structure of the gas-permeablesusceptor, 9. This inventions embodies a macroscopic artificialdielectric structure for the gas-permeable susceptor, 9. The embodiedgas-permeable macroscopic artificial dielectric susceptor can be eithera honeycomb structure, foam, or woven fabric filter with a pattern, or astructure consisting of discrete susceptors, which are known to thisinvention as unit susceptors. This invention embodies the gas-permeable,macroscopic artificial dielectric susceptor to allow for appliedelectromagnetic energy, 6, to penetrate the distance between theprimarily reflective components, whether a discrete susceptor, a coatingpattern or woven pattern structure so the structure does not act as acollection of waveguides with cut-off frequencies that prevents theapplied energy, 6, from penetrating the width of interaction, 12. Thegas-permeable, macroscopic artificial dielectric susceptor embodies a)an article constructed of a material where the article has a coatingapplied in a specific pattern to create a macroscopic artificialdielectric structure from the coating and the article b) a wovenstructure that contains two or more different materials as threads (oryarns) which woven together to form a macroscopic artificial dielectricstructure or c) a structure that consists of a mixture of discretesuscepting articles where the mixture contains discrete articles thathave different dielectric properties and surround each other to form amacroscopic artificial dielectric structure.

When the embodied invention, the gas-permeable macroscopic artificialdielectric structure, has a article which is a honeycomb structureconstructed of a material, some of cell walls of the honeycomb can becoating with materials that have different dielectric properties toproduce an macroscopic artificial dielectric. The pattern of cells withcoated walls are arranged in the honeycomb so that the appliedelectromagnetic energy and energies penetrate the suscepting structureand either heat the susceptor or scatter the energy for interaction withthe gases/particulate in the air stream. The pattern of the cell wallsattenuate the applied electromagnetic energy by either a) partially orcompletely by absorbing the applied energy, producing fluorescentradiation to heat the remaining parts of the susceptor and the airstream or b) partially or completely scattering applied energy toconcentrate the applied energy for interaction with the air stream or toheat the remaining volume of the susceptor. Also, the embodiedmacroscopic artificial dielectric can be made from the honeycombstructure by filling some of the cells with another material.Additionally, the invention embodies a large honeycombed-shaped,macroscopic artificial dielectric structure that is constructed from 1)smaller discrete susceptor articles that are small honeycombed shapedarticles that have differing dielectric properties and/or conductivityor 2) smaller discrete susceptor articles that are honeycombed shapedthat have the same dielectric property and are cemented together with amaterial which has different dielectric properties and/or conductivity.This invention also embodies the same or similar methods used to createhoneycombed-shaped macroscopic artificial dielectrics to be employed tocreate macroscopic artificial dielectrics out of foams and weaves.

When the embodied macroscopic artificial dielectric susceptor isdesigned as structure that consists of unit susceptors, susceptor can bedesigned for complex interaction with the applied energy or energies aspreviously described in Example 3. Potentially, each unit susceptorsusceptor can have separate characteristics for absorption,transmission, scattering and reflection of 1) applied electromagneticenergy or energies, 2) subsequent fluorescent radiation produced fromthe applied electromagnetic energy or energies and 3) the subsequentradiation from heat resulting from the dielectric loss within eachindividual susceptor. The separate characteristics of absorption,transmission, scattering and reflection of a unit susceptor embodied inthis invention are controlled by the unit susceptor's length, thickness,shape, composite materials structure, material selection, porosity, poresizes, temperature dependence of the complex dielectric constant andthermal conductivity.

FIG. 5 describes the structure macroscopic artificial dielectricsusceptor, 15, by using a two-dimension array of squares that representunit susceptors. Although the optical properties of each unit susceptorwithin the embodied macroscopic artificial dielectric susceptorstructure, 15, can be independent, the embodied structure of themacroscopic artificial dielectric susceptor, 15, will dictate theinteraction of the macroscopic susceptor with the appliedelectromagnetic energy, 6. The structure of the macroscopic artificialdielectric susceptor will be describe with the unit susceptors that areprimarily reflective, 16. This invention, the gas-permeable, macroscopicartificial dielectric susceptor, 15, embodies the principle ofreflection to provide diffuse reflection, scattering, as means forallowing the applied energy, 6, to penetrate the width of interaction,12, in susceptor, 9, to volumetrically interact with susceptor, 9, toproduce the method of desired method of treatment to react gases fordesired products or to treat pollutants for producing clean air whichcan be discharge into the environment in accordance with the law of theland. The reflectivity of the embodied macroscopic artificial dielectricsusceptor, 15 is controlled be the volume and interconnectivity of theunit susceptors, 16, which are the primarily reflective unit susceptorsin the macroscopic susceptor. The primarily reflective unit susceptors,16, are defined as being the unit susceptors to which are primarilyreflective to the applied energy, 6, or energies. The gas-permeable,macroscopic artificial dielectric susceptor has the primarily reflectiveunit susceptors, 16, surrounded by unit susceptors, 17, that are eitherprimarily transparent or partially absorptive of the applied energy orenergies. The primarily reflective unit susceptors, 16, scatter theapplied energy, 6, within susceptor, 9, concentrating the applied energyto interacted with either a) the primarily transparent or partiallyabsorptive unit susceptors, 17 or the reactant gases, pollutants orparticulates.

As the volume of the primarily reflective unit susceptors, 16, increasesin the gas-permeable, macroscopic artificial dielectric susceptor, 15, adegree of interconnectivity of the primarily reflective unit susceptors,16, will occur, forming an interconnective network within thegas-permeable, macroscopic artificial dielectric susceptor, 15, as shownin FIG. 6. The degree or amount of interconnectivity will depend on thesize and shape of the primarily reflective unit susceptors, 16. Theability of the applied energy, 6, or energies to penetrate themacroscopic artificial dielectric susceptor, 15,9, will depend not onlyon the volume of the primarily reflective unit susceptor, 16, but alsoon the degree and amount of interconnectivity. When the degree ofinterconnectivity of the primarily reflective unit susceptors, 16,throughout the entire gas-permeable macroscopic artificial dielectricsusceptor, 15,9, is such that maximum distance between theinterconnected network, 18, of the primarily reflective unit susceptors,16, does not allow for applied energy, 6, to penetrate or the longestwavelength of the applied energies, 6, to penetrate, the gas-permeablemacroscopic artificial dielectric susceptor, 9, 15, itself, will becomeprimarily reflective to either a) the applied electromagnetic energy orb) the longest wavelength of the applied energies, and volumetricinteraction between the applied energy, 6, with susceptor, 9 will notoccur. The volume of susceptor, 9, given by the production width ofinteraction, 12, by the length of the susceptor by the breadth of thesusceptor will not have 50% of the applied electromagnetic energydisturbed volumetrically within the volume. This invention embodies agas permeable susceptor with macroscopic artificial dielectric structurewhich allows for the applied electromagnetic energy, 6, to be able topenetrate the distance, 18, between primarily reflective unitsusceptors, 16, allowing for volumetric interaction within susceptor, 9.The embodiments of this invention can be applied to honeycombstructures, weaves and foams when reflective coating are applied to thestructure or the structure are constructed of smaller pieces that areprimarily reflective suscepting units.

The invention allow embodies a high degree of interconnectiviy ofprimarily reflective unit susceptors, 16. A high degree ofinterconnectiviy, can be beneficial in some instances. This inventionembodies the use of clusters of primarily reflective unit susceptors,16, to distributed about the macroscopic artificial susceptor to promotescattering. Primarily reflective unit susceptors can be aggregated toform shapes and boundaries that reflect one or more wavelengths of theapplied energy or energies.

This invention embodies a macroscopic artificial dielectric structurefor the gas-permeable susceptor, 9, where the volume fraction andinterconnectivity of the reflective unit susceptors, 16, surroundingpartially absorbing or primarily transparent unit susceptors, 17, as ameans to design a) specific macroscopic artificial dielectric structuresfor resonant cavities with that are based upon the wavelength of theapplied energy in the susceptor, b) specific macroscopic artificialdielectric structures for scattering energy for interaction with gas orparticulate species, c) specific macroscopic artificial dielectricstructures that concentrate energy at field concentrators which arelocated on other unit susceptors, d) specific macroscopic artificialdielectric structures which concentrate energy within the susceptor forincrease reactivity between the gas stream and the fluorescentradiation, e) specific macroscopic artificial dielectric structures thathave the primarily reflective unit susceptors arranged in such a mannerto produce a large spiral, helical or other shape with the macroscopicsusceptor f) specific macroscopic artificial dielectric structures thatas shielding to prevent the applied electromagnetic from enteringmaterial inside the cavity for thermal insulation, g) specificmacroscopic artificial dielectric structures that prevent leakageoutside the cavity by the applied energy, h) specific macroscopicartificial dielectric structures that reflect applied energy to otherregions of the artificial dielectric to provide either highertemperatures or increased energy for reaction or destruction ofgaseous/particulate species, and, specific macroscopic artificialdielectric structures that regulate the temperature of the gas-stream.

This invention also embodies a gas-permeable susceptor, 9, with amacroscopic artificial dielectric structure which uses reflection,scattering and concentration of the applied electromagnetic energy as ameans a) to react gases for desired products or to treat pollutants forproducing clean air which can be discharge into the environment inaccordance with the law of the land, b) to regulated the temperature ofthe air stream. c) prevent the device from overheating, d) to preventdeleterious reactions between the materials of construction, e) to heata gas stream, f) to create a device of substantial size for adsorptionand regeneration of gaseous species from a mixture of carbon-containingsusceptor and zeolite-containing susceptors and g) to produce a desiredratio of a self-limited temperature to power concentration of appliedenergy or energies to perform the desired utility.

This invention embodies primarily of the unit susceptors, 16, that areproduced from metallic or intermetallic materials species at roomtemperature or materials such as semiconductors, ferroelectrics,ferromagnetics, antiferroelectrics, and antiferromagnetics which becomereflective at elevated temperatures. The embodied unit susceptor'smaterials that produce reflection are either a) homogeneous materials b)a composite materials having a second phase material in a matrix that ispartially absorptive to applied electromagnetic energy where he volumefraction of the second phase materials can be used to control the amountof reflection of a unit susceptor or c) a coating on a unit susceptor.This invention also embodies the length, width and shape of theprimarily reflective unit susceptors, 16, and the distance betweenreflective unit susceptors, 18, to controlled the reflectivity of thegas-permeable, macroscopic artificial dielectric susceptor.

The shape of the unit susceptor can be designed for reflection. Theinvention embodies the shape of the unit susceptor that are eitherchiral, spirelike, helical, rod-like, ascicular, spherical, ellipsoidal,disc shaped, needle-like, plate-like, irregular-shaped or the shape ofspaghetti twist in Muller's Spaghetti and Creamette brand. Thisinvention embodies the shape the unit susceptor to produce turbulence inthe air flow, thus provide for mixing of reactants in the gaseous orliquid stream. The shape and size of the susceptor can be used to gradethe pore size of the susceptor to accommodate the expansion of gas dueto passing through the hot zone.

Another embodiment of this invention is unit susceptors, 19, that isillustrated in FIG. 7. Unit susceptors, 19 can make up thegas-permeable, macroscopic artificial dielectric susceptor, 15. The unitsusceptor's, 19, shaped can be chiral, spirelike, helical, rod-like,ascicular, spherical, ellipsoidal, disc shaped, irregular-shape,plate-like, needle-like or shape a Muller's spaghetti twist (rotini).The susceptor, 19, can be an artificial dielectric material, made from ahomogeneous material or have a coating on the unit susceptor that iseither made from a homogeneous material or artificial dielectricmaterial. The length of unit susceptor, 19, should be greater than 0.25inches and width should be greater than {fraction (1/16)}th of an inch.

The absorption, transmission, reflection, scattering and the complexdielectric constant of unit susceptors, 19, can be controlled by usingartificial dielectric materials. The structure of a unit susceptors, 19,made from an artificial dielectrics materials is shown FIG. 7. The unitsusceptor, 19, has a matrix material, 20, which contains a second phasematerial, 21 or third phase material, 12. The purpose of using anartificial dielectric materials for a unit susceptor, 19, is to produceprimarily reflective unit susceptors, 16. The reflectivity of theprimarily unit susceptors, 16, can be controlled by size, volumefraction and shape of the 2nd phase material, 21 or third phasematerial, 21. A volume fraction of the second phase material over 50%can produce an interconnected network of the 2nd phase materials whichhas a reflectivity that behaves the same as higher volume fractions. Theshape of the second phase can be chiral, spirelike, helical, rod-like,ascicular, spherical, ellipsoidal, disc shaped, irregular-shape,plate-like or needle-like. A size range of the 2nd phase, 21, which isfrom the group of materials known as semiconductors, conductors,ferromagnetics, ferroelectrics, ferrimagnetics and antiferroelectrics isembodied in this invention. The size-range which is embodied in thisinvention for the 2nd phase is a particle size range that is −325 U.S.Mesh Sieve Size or less (equivalent to sizes less than 46 microns). Theembodied small particle size range is used because these particle sizeswill rapidly absorb electromagnetic energy, elevating the temperature ofthe particles very high temperature where the particles' material willbecome very conductive and/or exceed the Curie Temperature, renderingthe unit susceptor to be reflective. Another embodiment of thisinvention is that the thermal expansion mismatch between the 2nd phasematerial, 21, and the matrix, 20, be less than 15%, in order to preventthe unit susceptor, 19, from becoming friable. Another embodiment ofthis invention is a method to reduce the thermal expansion mismatch byhave the unit susceptors 2nd phase material, 21, being a the samecrystalline structure and base material as the matrix material, 20,however the 2nd phase's material, 21, is doped on the lattice structurewith a cation or anion to increase the electrical conductivity of thesecond phase's material while producing a very low thermal expansionmismatch between the matrix, 20, and the second phase, 21. Anotherembodiment of this invention is to have the size of the 2nd phaseparticle, 21, be in the size range of between 200 microns and 3 mm inthe unit susceptor, 19, when strong potential for deleterious chemicalreaction between the matrix, 20, and the 2nd phase material, 21, in unitsusceptor, 19.

Additionally, the composite materials for unit susceptors can use acombination of materials in such a fashion where selected materialswhich produce thermoluminescent, incandescent and phosporesentradiation.

An other embodiment of this invention is the use of field concentrators,22, on unit susceptors, 19, as illustrated in FIG. 8. This inventionembodies the use of field concentrators, 22, to concentrate theelectromagnetic locally so a high intensity electromagnetic field isavailable to interact with gaseous/particulate species to either drivechemical reaction, enhance the reaction between chemical species or totreat pollutants. This inventions embodies materials of construction offield concentrators, 22, that are a) conductors, b) semi-conductors, c)materials with a Curie Point, d) ionic-conducting ceramic, e) acomposite materials from a and c, f) a composite materials form b and c,g) composite materials from a and d and h) composite materials from band d. This invention embodies the shape of field concentrators, 22, tobe selected from shapes that are chiral, spirelike, helical, rod-like,ascicular, spherical, ellipsoidal, disc shaped, irregular-shape,plate-like, needle-like or have a shape that has sharp-pointed-gear-liketeeth. This invention embodies the a size range for the fieldconcentrators, 22, that is used to prevent deleterious chemical reactionbetween the field concentrators, 22, and unit susceptor, 19. The size ofthe field concentrators can be one to 10 times the depth of penetrationof applied electromagnetic energy of material construction, either atroom temperature or the operating temperature. This size differencedepends on the chemical compatibility between the field concentratorsand the unit susceptor's materials of construction. Where there islittle concern for deleterious reaction between the unit susceptor andfield concentrator, then the size of the field concentrator, which,based on its depth of penetration of the materials of construction, canbe 1 to 10 times the depth penetration at the operating temperature. Ifthere is great concern for deleterious reaction between the unitsusceptor and field concentrator, then the size of the fieldconcentrator should be such not to promote reaction, 200 microns to 4mm. Additionally, this invention embodies the use of a a barriercoating, 23, between the field concentrators, 22, and the unitsusceptor, 19, to prevent deleterious chemical reaction between thefield concentrator and the unit susceptor. Also, this invention embodiesthe following materials of construction for field concentrators, 22,this materials include 1) a thermoluminescent material, 2)aphosphoresent material, 3) an incandescent material 4) ferroelectric, 5)ferromagnetic, 6) ferrimagnetic, 7) MnO₂, 8) TiO₂, 9) CuO, 10) NiO, 11)Fe₂O₃, 12) Cr₂O₃, 13) Li₂O doped MnO₂, 14) Li₂O doped CuO, 15) Li₂Odoped NiO 16) CuO—MnO₂—Li₂O complex 17) CuO—MnO₂ 18) silicide, 19)borides, 20) aluminides, 21) nitrides, 22) carbides, 23) ceramic glazeswith metal particles, 24) ceramic glazes with semi-conducting particles,25) materials that produce thermionic emissions and 26) thermoelectricmaterials.

This inventions embodies the production of ozone from fieldconcentrators, 22, on unit susceptor, 19 as shown in FIG. 8. When thedistance (gap), 23, between two field concentrators, 22, which are madefrom materials which are conducting or semi-conducting are at such adistance, the applied electromagnetic field, 6, can cause a discharge ofa spark from localized fields that are produced by the appliedelectromagnetic energy, producing ozone. The invention also embodies theproduction of ozone on the surfaces of unit susceptors, 19, which thatare constructed of artificial dielectric material as shown in FIG. 7. Aspark can occur from a gap, 24, between the exposed surfaces of the 2ndphase material, 21, and ozone can be produce. This invention embodiesthe production of zone for that can occur at elevated temperatures andwhen the volume fraction of the 2nd phase material, 21. exceeds twentypercent (20%). Also, this invention embodies the production of ozonefrom electric discharges that can occur a) between two unit susceptors.19 in close proximity that contain field concentrators, 23, b) betweenexposed surfaces of 2nd phase material, 21, from two unit susceptors inclose proximity and c) between two unit susceptors, 19, where one unitsusceptor, 19, contains a field concentrator. 23, and the one unitsusceptor contains an exposed surface of a 2nd phase material, 21.

I Claim:
 1. Device which uses applied electromagnetic energy fortreatment of a chemical species flow comprising, in combination: (a) acavity which has a cross-sectional area that is normal to the flow ofthe chemical species flow, said cross-sectional area being shaped as anirregular-shaped polygon of four (4) or more sides, wherein the twosides that are parallel to each other are elongated, producing thegreatest dimension of the said cross-sectional area known as the length;(b) at least one opening located on each parallel side of the greatestdimension of the said cross-sectional area as a means for the appliedelectromagnetic energy to enter the cavity; (c) an inlet where thechemical species flow enters the cavity with said inlet having a meansto prevent the applied electromagnetic energy from escaping the cavity;(d) a gas-permeable susceptor which provides a means for a desiredtreatment of the chemical species flow by volumetric interaction withthe applied electromagnetic energy by having the depth of penetration ofsaid susceptor by the applied electromagnetic energy being no less thenone-third the width of the said susceptor, where a least 50% of theapplied energy in the cavity volumetrically interacts with saidsusceptor by the volume that is given by the product of the width ofinteraction by the said susceptor's breadth by the said susceptor'slength having the cavity extended in the direction of the breadth of thecavity as a means to provide a designed resident time for the desiredtreatment of the chemical species flow; and (e) an outlet where thetreated chemical species flow leaves the cavity with said outlet havinga means to prevent electromagnetic energy from escaping the cavity. 2.The device characterized in claim 1, further comprising lenses in thesaid at least one opening where the applied electromagnetic energyenters the cavity.
 3. The device characterized in claim 1, furthercomprising a means for thermally insulating the cavity from heatgenerated in said susceptor by the applied electromagnetic energy byusing an aerogel constructed of a material which is transparent to theapplied electromagnetic energy and a thin insulating layer between theaerogel and said susceptor that acts as a barrier that prevents thechemical species flow passing through the device from transferring heatto the cavity by convection or radiation.
 4. The device characterized inclaim 1, further comprising rectangular waveguides that intersect thecavity at oblique angle, producing a large opening allowing the appliedelectromagnetic energy to enter the cavity.
 5. The device characterizedin claim 1, wherein said susceptor is constructed of an artificialdielectric material.
 6. The dielectric susceptor characterized in claim5, wherein said dielectric susceptor comprises a matrix and at least onenon-matrix material, said matrix being selected from the group ofmaterials consisting of low-loss dielectric materials, thermoluminescentmaterials, and fluorescent materials.
 7. The dielectric susceptorcharacterized in claim 6, wherein the low-loss dielectric material isselected from the group consisting of alumina, aluminosilicate ceramic,clay, zeolite, magnesium oxide, magnesium-silicate ceramic, steatite,enstatite, nitride, sialon, oxynitride, high-temperature porcelain,polymeric organic, inorganic glass, organic glass, and Teflon.
 8. Thedielectric susceptor characterized in claim 6, wherein the non-matrixmaterials are selected from the group consisting of glassy, metallic,ferrimagnetic, ferroelectric, ferromagnetic, semiconducting, conducting,solid-state ionic conducting, non-stoichiometric carbide,non-stoichiometric oxide, oxycarbide, oxynitride, carbonitride,intermetallic, thermoluminescent, and fluorescent materials, andcombinations thereof.
 9. The dielectric susceptor characterized in claim8, wherein the ferromagnetic material is selected from the groupconsisting of FeO, CuO, Cu₂O, MnO₂, Mn₂O₅, NiO, Fe₂O₃, Fe₃O₄, CuO—MnO₂,Cu₂O—MnO₂, Li₂O—Cu₂O, Li₂O—CuO, and Li₂O—MnO₂.
 10. The dielectricsusceptor characterized in claim 8, wherein the non-matrix material isselected from the group consisting of TiC_(x−y)O_(y), TiC_(2−x), TiO₂,stabilized-zirconia, Na-beta alumina, Li-beta alumina, (Na,Li)-betaalumina, alpha-alumina, SiC, anatase and beta″-alumina.
 11. Thedielectric susceptor characterized in claim 6, wherein the volumefraction of the non-matrix material is distributed homogeneouslythroughout the materials of construction.
 12. The dielectric susceptorcharacterized in claim 6, wherein the non-matrix materials are grouptogether to form discrete regions.